X vs H (both O/R)

Got my car away for the winter and i wanted to throw a mid pipe on there, but i have a few questions for you all. Whats the difference between the X and H pipes? I will be going with the O/R version of either. I had a o/r h on my 95 gt, and it sounded good. But i see alot of people with x pipes, and i must say i have never heard one in person, or seen them compared to a H pipe. Also, my exhaust manifold is stock right now, so am i looking for a particular length mid-pipe? And will this mid-pipe still fit when i get my FFRP shorties in the spring? Thanks for your help, Cant wait to get somthing more installed!!
 
The X will give you better flow (more power up top) and some people think they are more raspy.
The H will give you a bit more torque at lower RPM because of the hight delta pressure moving the power down. Also deeper sounding.

I think most of the mid's will hook up to the stock exchaust (if they dont they will say so) But like the SLP o/r X it will fit both the stock or shorty headers or the long tubes. I personaly would go for LT and get better flow. I plan to put the whole SLP set up on hopefully in early spring.